Moisture management remains the most important critical factor for controlling mold growth on wood and wood products during storage, construction and in service. Potential health risks caused by mold growth in houses and non-residential wooden structures have been a major concern for homeowners, building contractors and insurance companies alike. Law suits claiming health problems caused by indoor mold exposure exceeded 2.8 billion dollars in 2002.
Chemical fungicides commonly used to control the growth of mold on wood are not appropriate for many indoor applications. Natural alternatives that are user friendly and demonstrate low toxicity to humans are desirable for indoor applications. Essential oils are known for their natural, non-toxic components including monoterpenes, diterpenes, and hydrocarbons with various functional groups.
In the early 1990's, it was reported that bioactive plant extracts may be effective against bacteria and fungi. (See Muanza K et al., Antibacterial and antifungal activities of nine medicinal plants from Zaire, Int. J. Pharmacog. 32:337-345 (1994); and Muanza D N et al., Screening for antitumor and anti HIV activities of nine medicinal plants from Zaire, Int. J. Pharmacog. 33:98-106 (1995)). Antimicrobial and antifungal activities of essential oils in food applications, pharmaceutical research and other scientific areas have also been reported. (See Cowan M M, Plant products as antimicrobial agents, Clin. Microbiol Rev. 12:564-582 (1999); Hammer K A et al., Antimicrobial activity of essential oils and other plant extracts, J. Appl. Microbiol. 86:985-990 (1999); Hoffman B R et al., Screening of antibacterial and antifungal activities of ten medicinal plants from Ghana, Pharmaceutical Biology 42(1): 13-17 (2004); Mau J L et al., Antimicrobial effect of extracts from Chinese chive, cinnamon and Corni fructus, J. Agric. Food. Chem. 49:183-188 (2001); Sivropoulou A et al., Antimicrobial activity of mint essential oil, J. Agric. Food Chem. 43:2384-2388 (1995); Adam K et al., Antifungal activities of Origanum vulgare subsp. Mentha spicata, Lavandula angustifolia and Salvia fruiticosa essential oil against human pathogenic fungi, J. Agric. Food Chem. 46:1739-1745 (1998); Deferera D J et al., Analysis of essential oil from some Greek aromatic plants and their fungitoxicity on Penicillium digitatum, J. Agric. Food. Chem. 48:2576-2581 (2000); Moretti et al., In vivo activity of Salvia officinalis oil against Botrytis cinera, J. Essent. Oil Res. 10:157-160 (1998); Muller-Riebau F et al., Chemical composition and fungitoxic properties to phytopathogenic fungi of essential oil of selected aromatic plants growing wild in Turkey, J. Agric. Food. Chem. 43:2262-2266 (1995); Rakotonirainy M S et al., Screening for antifungal activity of essential oils and related compounds to control the biocontamination in libraries and archives storage areas, International Biodeterioration ad Biodegradation 55:141-147 (2005); Scheffer T C et al., Fungistatic vapors for control of mold in packages and equipment, Industrial and Engineering Chemistry 38:619-621 (1946); Sridhar S R et al., Antifungal activity of some essential oils, J. Agric. Food. Chem. 512:7596-7599 (2003); and Wang S-Y et al., Antifungal activities of essential oils and their constituents from indigenous cinnamon (Cinnamomum osmophloeum) leaves against wood decay fungi, Bioresource Technology 96:813-818 (2005)).